EDD to DTD conversion

I am using FM 8 on Windows XP Pro and just working through the Getting started with structure example. It's a breeze until I get to the "Building the structured application" topic. Then, whenever I try to save the EDD as a DTD, I get these XML parsing errors:

Invalid document structure
The main XML document cannot be empty
Syntax error
Parsing aborted

I also tried reading in some of the many EDD files loaded with the application and saving them as DTD, but they have parsing errors as well. Does anyone have any ideas what is going wrong here?

Cheers,

John